//Circular Doubly Linked List
#include <stdio.h>
#include <stdlib.h>
typedef struct node
{
int info;
struct node *next;
struct node *prev;
}NODE;
void createlist(NODE *list);
void display(NODE *list);
void search(NODE *list);
void insert(NODE *list, int num, int pos);
void delpos(NODE *list, int pos);
void delvalue(NODE *list, int num);
void main()
{
int pos, num, n, no;
NODE *list=(NODE*)malloc(sizeof(NODE));
list->next=list;
createlist(list);
display(list);
printf("\n");
do
{
printf("\nOperation on Doubly Linked List:");
printf("\n1. Insert:");
printf("\n2. Display");
printf("\n3. Search");
printf("\n4. Delete by position");
printf("\n5. Delete by value");
printf("\n6. Exit\n");
printf("\n Enter your choice:");
scanf("%d", &no);
switch(no)
{
case 1: printf(" Enter the node data:");
scanf("%d", &num);
printf("Enter the node position to insert node:");
scanf("%d", &pos);
insert(list, num, pos);
display(list);
printf("\n");
break;
case 2: printf(">>Circular Doubly Linked List<<\n");
display(list);
printf("\n");
break;
case 3: search(list);
display(list);
printf("\n");
break;
case 4: printf("Enter node position to be delete that node:");
scanf("%d", &pos);
delpos(list, pos);
display(list);
printf("\n");
break;
case 5: printf("Enter node data to be delete :");
scanf("%d", &num);
delvalue(list, num);
display(list);
printf("\n");
break;
case 6: printf("End\n");
break;
default:
printf("\n>>Enter Valid Choice<<\n");
}
}
while(no!=6);
}
void createlist(NODE *list)
{
int n, i;
NODE *temp=list, *nn;
printf("How Many Nodes you want to enter ?\n");
scanf("%d", &n);
for(i=1; i<=n; i++)
{
nn=(NODE*)malloc(sizeof(NODE));
printf("\n Enter the node data:\t");
scanf("%d", &nn->info);
nn->next=list;
temp->next=nn;
temp->prev=temp;
list->prev=nn;
temp=nn;
}
}
void display(NODE *list)
{
NODE *temp;
for(temp=list->next; temp!=list; temp=temp->next)
{
printf("%d", temp->info);
printf("--->");
}
}
void search(NODE *list)
{
int num, flag=0;
NODE *temp;
printf("Enter Element to search:\t");
scanf("%d", &num);
for(temp=list->next; temp!=list; temp=temp->next)
{
if(temp->info==num)
{
printf(">>%d is found<<\n", num);
flag=1;
exit;
}
}
if(flag==0)
printf(">>%d is not found<< \n", num);
}
void insert(NODE *list, int num, int pos)
{
NODE *nn, *temp=list, *temp1;
int i;
nn=(NODE*)malloc(sizeof(NODE));
nn->info=num;
for(i=1, temp=list; temp->next!=list && i<pos; i++)
temp=temp->next;
if(i<pos)
{
printf("Position is out range\n");
return;
}
temp1=temp->next;
nn->next=temp1;
temp1->prev=nn;
temp->next=nn;
nn->prev=temp;
}
void delpos(NODE *list, int pos)
{
NODE *temp=list, *temp1, *temp2;
int i;
for(i=1,temp=list; temp->next!=list && i<pos; i++)
temp=temp->next;
if(i<pos || temp->next==list)
{
printf(">>Position is out of range<<\n");
return;
}
temp1=temp->next;
temp2=temp1->next;
temp->next=temp2;
temp2->prev=temp;
free (temp1);
}
void delvalue(NODE *list, int num)
{
NODE *temp=list, *temp1, *temp2;
if(list->info==num)
{
list=list->next;
free (temp);
return;
exit;
}
for(temp=list; temp->next!=list; temp=temp->next)
{
if(temp->next->info==num)
{
temp1=temp->next;
if(temp1->next==NULL)
{
temp->next=NULL;
free (temp);
return;
exit;
}
else
{
temp2=temp1->next;
temp->next=temp2;
temp2->prev=temp;
free (temp1);
return;
exit;
}
}
}
printf(">>Enter valid data<<\n");
return;
}
